The invention relates to a slide track structure especially for slidably supporting passenger seats and locking them in predetermined positions.
Slide tracks of this type have either friction bearings or they have ball or roller bearings. Especially for passenger seats, slide tracks with friction bearings have been preferred, so far, because this type is generally more suitable for the requirements of movability and lockability of passenger seats. Passenger seats, for example, in spite of their adjustability, must be securely mounted on a vehicle chassis such that they can withstand relatively forceful crashes, they must be so mounted that they give the occupant the feeling of being safely seated. That is, they cannot be mounted in a floating manner, but they must be safely locked in any desired position; the adjustment mechanism must have a relatively long life; and, especially, they must remain rattle-free at all times no matter whether the seat is occupied or not.
Although the requirements of secure mounting can be achieved for slide tracks with friction bearings as well as for those with anti-friction bearings, it is generally much easier to make slide tracks with friction bearings rattle-free. On the other hand, slide tracks with anti-friction bearings have a longer operating life than those with friction bearings.
Since a long operating life which should be at least as long as the life of the seats is required, more and more seats are provided with slide tracks with ball or roller bearings. Freedom of rattling is generally achieved for such slide tracks by additional balls or rollers which are preloaded by springs or elastomer material and force the two relatively movable tracks of the slide track into engagement with each other. This is naturally done in the load direction of a seat such that a preload is applied to the slide track in a loading sense. Added thereto is the actual load when a seat is occupied by a passenger so that these slide tracks must be very sturdy and, consequently, quite heavy. In addition, the seats are not easy to move and require relatively large operating forces for changing the seat position.
Since, however, also relatively weak persons should be able to adjust the seats, seat support slide track should be easily operable.
It is therefore the object of the present invention to provide a seat slide track which provides for secure connection between a solidly mounted support and a part which is movable relative to the support, which is lightweight and rattle-free, which is easily movable and which is simple and inexpensive to manufacture.